Chromium in the factory is pronounced as "Luo" because this element was pronounced as "Luo" before 1985, and later it was pronounced as radical in order to be consistent with the pronunciation of chemical terms.
However, due to people's deep impression and cognition of this element in daily life, chromium is still widely pronounced as "Luo" in factories.
In addition, the word with the word "ge" beside it that can be associated with metal is the brand of "soldering iron", and its pronunciation is also Luo, thus further deepening people's understanding of the pronunciation of "Luo" of chromium.
1, the meaning of chromium
Chromium, chemical symbol Cr, atomic number 24, belongs to group ⅵ b in the periodic table of elements. The name of the element comes from Greek, which means "color", because all chromium compounds have colors. Simple substance is steel gray metal, which is the hardest metal in nature.
The content of chromium in the crust is 0.0 1%, ranking 17. Free natural chromium is extremely rare and mainly exists in chromite.
2065438+07101The list of carcinogens published by the International Agency for Research on Cancer of the World Health Organization was preliminarily sorted out for reference. Metal chromium is in the list of three types of carcinogens.
2. The discovery history of chromium
In 1797, the French chemist Walker discovered chromium from what was then called the red Siberian ore. As early as 1766, Liemann, a German chemistry professor in St. Petersburg, Russia, analyzed it and determined that it contained lead.
1798, Vauclin named the gray acicular metal he discovered chrom, which comes from the Greek word chroma. From this, the Latin name of chromium and the element symbol Cr are obtained. At about the same time, klapp Lott also independently discovered chromium from chromite.
3. Element distribution of chromium
It mainly exists in the form of chromite FeCr2O4 in nature. It is formed by reducing chromium oxide with aluminum, or electrolyzing chromite or chromic acid.
According to its content in the earth's crust, chromium is one of the widely distributed elements. More cobalt, nickel, molybdenum and tungsten than previously found.
This may be because the natural compounds of chromium are very stable, insoluble in water and difficult to reduce. Some people think that the metal chromium obtained by Vauclin may be chromium carbide.